The present invention relates to a Time Division Multiple Access (TDMA) radio communication system and, more particularly, to a repeater station in the TDMA radio comunication system.
A system of this type is normally constituted by an exchanger connected to a plurality of subcribers, a base station which is connected to the exchanger and has a radio transmitter/receiver so as to link the radio subscribers within its service zone (home zone) with the exchanger, and a plurality of repeater stations which have individual home zones and provides repeater services to the radio subscribers within the corresponding home zones. The repeater station closer to the base station is referred to as a "higher" repeater station towards the others, and the repeater station at longer distance from the base station than others is referred to as a "lower" repeater station towards the others.
Each repeater station has a downward receiver for receiving a downward signal from the higher repeater station, a downward transmitter for transmitting the downward signal to the lower repeater station, an upward receiver for receiving an upward signal from the lower repeater station, and an upward transmitter for transmitting the upward signal to the higher repeater station.
Communication between subscribers is time-divisionally performed, and at least one time slot is assigned to one communication (single speech or data).
Conventionally, when a radio subscriber in the home zone of a higher repeater station communicates with a subscriber connected to the exchanger via the base station, the downward transmitter of the higher repeater station is operated over all the time slots. More specifically, even though a subscriber in the home zone of a lower repeater station does not perform communication, a downward transmitter of the higher repeater station is driven, thus wasting power.